The invention relates to machine for dislocating stacks by means of a milling cutter, which is laterally guided along a stack in a driving direction and through which a layer of material is removable from the stack through milling during each passage, the machine having a conveying device, onto which the material removed by milling drops and which is used to deposit the material in an area offset from the milled stack.
The invention particularly relates to the dislocating of stacks out of biological waste as, for example, branches, shrubs or biological waste.
Biological waste is put on stacks to finally, be decomposed to humus. These are stacks of a height and a width of several meters and often a length of hundreds of meters. The material able to be decomposed has to be dislocated from time to time in order to supply air oxygen to the stack and, thus, to support the decomposing process. If the stack is not dislocated, then the decomposing process is delayed. Furthermore, anaerobic zones arise, in which decomposing takes place under strong smell irritation.
After several dislocations in time intervals, which depend on the type of material, the material in the stacks are, to a large degree, decomposed to humus. Then, the material is supplied to a sieve machine. This sieve machine separates components which have not been decomposed. Furthermore, foils and pieces of plastic are separated. The components which have not been decomposed are supplied to the new stacks. The sieved, decomposed earth can be filled into sacks and be sold.
Several machines are known, through which this dislocation of stacks is to be done by machines.
With a prior art type of machines, a stack with a width of, for example, five meters is taken up from the front side. For this purpose, a vehicle is provided, the wheels of which run on the side of the stack and which takes up the material at the front and transports it over the vehicle, such that the material is put dawn behind the vehicle. Such a vehicle is very complicated. Free areas have to be provided on both sides of the stack. The vehicle is a single-purpose vehicle, which cannot be used for other purposes.
With another type of machines, a drum rotating about a vertical axis of rotation is guided along the stack. Then, cutting tools on the circumference of the drum remove layers from the stack. The removed material falls on a conveying device and is put down again as new stack in an area offset from the original stack. Such devices removes just a relatively thin layer from the stack through milling. If the roller is pushed to far toward the stack, then the repulsion force will be high. The machine is pushed back again. A further disadvantage of these known machines is that plastic foils often being present in the moved material are comminuted by the milling drum to such an extent that they cannot be separated anymore from the earth produced by decomposing.
The working life of the known machines is quite restricted.
In practice, the prior art machines did not work satisfactorily.
It is the object of the invention to construct a machine for dislocating stacks such that they allow a high throughput (dislocated material per unit of time), do not require any additional space between the stacks and enable long working time.
According to the invention this object is achieved in that the milling cutter has two lateral rotating milling heads, the rotation axes of which extend substantially in the driving direction or form an acute angle relative to the driving direction.
The machine is moved with the milling heads along the stack usually by means of a carrier vehicle. The milling heads cut into the material of the stack substantially in the driving direction. The resistance acting upon the milling heads acts against the driving direction and, thus, not transverse to the driving direction. During each passage, the two milling heads can remove by milling from the stack a wide strip corresponding at least to the radius of the milling head. The milling can also be effected transversely to the feed direction of the stacks. The milling heads can be very robust and are strained in longitudinal direction of their axes. This ensures long working life.
In an advantageous embodiment of the invention the milling heads are disc- or plate-shaped. Each one of the milling heads can form a plate vaulted in the driving direction and provided with milling bodies at its front side. Suitably, the milling heads are truncated cone-shaped. The milling heads are arranged one above the other. A plane extending through the rotation axes of the milling heads is inclined towards the stack by an angle which prevents the stack from collapsing in the milling plane. On a portion remote from the stack, the milling heads are covered by a cap which guides the material removed by milling to the conveying device. The milling heads rotate in the same direction. The described construction allows the milling heads to rotate with a rotary speed of more than 100 rpm.
Preferably, means for supplying water to the material transported on the conveying device are provided.
The machine is arranged to be driven by the power take-off shaft of a carrier vehicle. Thus, the drawing vehicle can be used for other purposes.
An embodiment of the invention will now be described in greater detail with reference to the accompanying drawings.